| The VRV mini central air condition system is the upscale system which can satisfy many machines indoors by one outdoors, extensively applied in the business and family, so it is the trend that the small air condition system develops in the future. Because the system is characteristic of multi-variables, strong coupling and nonlinearity, the key problem of saving energy sources is to set up the model of VRV system and describe it's performance.Aiding by ShenYang science and Technology item and the Education fund item of province, this text is carrying on the modeling research, which can be divided into three parts:Firstly, acting the principle of the conservation to the energy and quality, it sets up the mechanism model of the exchangers and deduces the nonlinear expression. The mechanism model from the outlet of the evaporators to the entrance of the compressor is considering the decline of the tube presses and the equilibrium principle of mass rate.Secondly, it deduces the state space model used for the controller design on the foundation of the mechanism model .For the exchangers, it obtains the state matrix by one step Taylor expanding to the state equation at the working point, and brings forward the method to confirm the parameter in the state matrix. For engineering need, it reduces order of the evaporator's state space model and adopts the condensers' one order model based on the energy balance principle. For pipeline and compressor, it obtains the state space which takes the entrance presses of compressor as output by the differential to the variable. It researches the integration method of the each part's model and analyses performance of each integration method, finally it takes the model using correlation of each part and physical analysis as the final model.Finally, it emulates the model and the data indicates that the method can truly reflect the running estate of the VRV system at the working point around. The model accuracy attains the engineering request.
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